wow... waste of time.
If people want to believe there are vampires out there I'd say leave them alone. Besides, they make great reading and watching material(vampires chronicles, the historian Buffy, Angel..etc.)
In many cases it is not everyone bitten turns into a vampire, and in the original lore it's the third bite that would turn you whereas more recently it's only if the vampires drinks the person, then the person drinks from the vampire and they turned.
....yes I like vampire stories, what else is new...